Treatment of animal and vegetable oils



Patented July 31, 1945 srics TREATMENT. OF ANgiVILQL AND VEGETABLE Loran Old Buxton,

to National Oil Products Company,

East Orange, N. 3., assignor Harrison,

N. .l., a corporation of New Jersey No -Drawing. Application July 29, 1942, Serial No. 452.7%

- duced from the fatty acids of shorter length, e. g.

o 13 Claims.

This invention'relates in general to the treatment of animal and vegetable oils and particularly to a process for the production of soap and high iodine value oils.

For many years linseed oil has been the oil principally employed in paints and varnishes to give them their characteristic drying properties. Because of the somewhat erratic fluctuations in the flaxseed crop, the price of linseed oil is relativelyhigh. Because of this and other reasons, a number of substitutes for linseed oil have been proposed. Vegetable oils such as soybean oil and similar oils have been suggested, but, al-

though they may be used in admixture with linseed oil, they are not satisfactory as they form soft, gummy films. Fish oils may also be used in conjunction with linseed oil, but even though they usually have a muchhigher iodine value than the vegetable oils and are fairly rapid .driers, they also form soft, tacky films and are therefore no more applicable for use alone than are the vegetable oils. Much work has been done, along the line of developing new or known but not extensively grown plants for producing drying oils and also along the line of chemical processing of the relatively cheap and available oils now used in admixture with linseed oil in order to producedrylng oils, but, as yet, no satisfactory,

readily available, economical replacement for linseed oil for use in paints-or varnishes has been developed. a

In the present art of soap making, fatty materials, i. e. ,oils, fats, fatty acids, etc.,' are saponified with various alkaline metal agents. Soaps produced in such a manner usually contain as constituents thereof fatty acid radicals which.

contain unsaturated linkages which are relatively unstable towards oxidative changes induced by the atmosphere, light and other oxidizing influences. It is thus necessary in many instances to add to soaps of such nature various materials knorsn as antioxidants in order to provide stable soaps. Naturally this increases the cost of such soaps and furthermore in many instances such antioxidants have deleterious effects on the soaps such as, for example, causing darkening thereof, imparting undesirable odors thereto, etc. Furthermore, any highly unsaturated constituents present in the soap tend to decrease the detergent qualities thereof. Moreover, due to the fact that soap contains a mixture of fatty acid radicals of varying chain lengths, the detergent properties of the soap are diminished since, as is well known,

fatty acids of twelve, fourteen, sixteen and in some instances even eighteen carbon atoms.

It isthe object of this invention to provide a process for producing drying oils from semidrying oils of vegetable and animal origin.

It is a further object of this invention to provide an improved process for increasingthe iodine value of fatty materials of vegetable and animal origin.

Another object of the invention is to provide improved drying oils for use in paints, varnishes and similar materials.

Still another object of the invention is to provide a process for producing soaps which are improved in their stability toward oxidative deterioration and which have improved detergent properties. A

I have found that animal and vegetable oils and fats may be selectively and partially sapo'nifled by carrying out the saponification at a comparatively slow rate under controlled conditions whereby the more saturated components and the shorter chain fatty acid components of the fatty material are more readily saponifled than the less saturated components. .Thus by partially asponifying such fatty materials under conditions conducive to selective saponiflcation, it is ossible to obtain a number of products, each more valuable than the fatty material itself. That fraction of the oil which is more readily saponifled is the more highly saturated portion thereof and This fraction is particularly applicable for the production of soaps since soaps produced therefrom contain very little, if any, highly unsatur-' ated fatty materials. Such soaps are superior to soaps containing. appreciable amounts of unaaturated fatty material since the presence. of

fatty acids of the longer chain lengths produce,

soaps which are not as efflclent-as those prohighly unsaturated fatty materials in the soap tends to lower the detergency and the stability thereof. Furthermore. there is no unsaponiflable matter present in the soap as is the case with soaps produced by the complete saponification of most fatty material. This is another factor tending to improve the quality of the soaps since, of course, any unsaponiflable matter present in the soap mass reduces to that extent the percentage of effective detergent matter. Also the unsaponiflable material in a fatty substance usually contains a certain amount of undesirable odoriferous substances, and a certain amount of unsaturated material which is relatively unstable and readily oxidized. The presence of such unsaponiflable material in a soap tends, of course, to lessen the desirability and stability thereof. That fraction of the fatty material which is not saponifled during the selective partial saponiflcation contains the more highly unsaponifled components thereof. terial has many valuable uses, depending to some extent, of course, upon the degree of unsaturation. The fatty material which has an iodine value of about 90 or above is particularly valuable as a drying and semi-drying oil for use in paints, varnishes and similar products.

I have found that, in order to get the desired selective saponiflcation, it is very important that the saponiflcation reaction proceed slowly under controlled conditions. If the reaction is carried out at a falrly'rapid rate, as is usually the case, as. in soap manufacture, the saponificatiomwill not be selective, but instead the more highly unsaturated components of the oil will be saponifled as readily as the saturated components. Consequently, even though the oil may be only partially saponifled, if the reaction is carried out at a fairly rapid rate, the portion of the oil which is not saponified will have practically the same degree of unsaturation as the original oil.

I have found, contrary to the general belief,

that the ester linkages between the more saturated, the shorter chain and the lower molecular weight fatty acids and glycerol are not as strong as the ester linkages between the unsaturated fatty acids and glycerol; consequently, the former are more easily broken and if the conditions of saponiflcation are properly controlled, such linkages will be ruptured whereas the linkages between the more unsaturated fatty acids and glyc- Such unhydrolyzed unsaturated fatty macaustic alkali, aqueous potassium hydroxide or sodium hydroxide being preferred, into the solvent diluted oil, care beingtaken to insure thorough mixing and to avoid too rapid saponifica tion. From about 25% to about 95%, preferably from 30% to 90% of the amount of alkali theoretically required to completely saponify all of the .saponifiable material contained in the oil is added.

ethanol, methanol, etc., to aid in bringing about a reaction between the oil and the alkali. This is particularly true when saponifying in the presence of a solvent. 01' course the rate of saponification may be slowed down by reducing the is carried out at room temperature.

amount of saponification catalyst used, or by not using any at all, also by using a less concentrated alkali, etc. If desired, saponiflcation inhibitors may be used to retard the rate of reaction; however, that is seldom necessary when the reaction Also, if desired the rate of saponiflcation may be retarded by carrying the reaction out at a temperature below room temperature.

In separating the unsaponified portion of the oil from the resulting soaps, I prefer to extract the partially saponified mass with a hydrocarbon or halogenated hydrocarbon solvent, such as one of the solvents suitable for-use in diluting the oil prior to the saponiflcation-step, and preferably the same solvent as was used during the saponificationstep. Before extracting the selectively partially saponified mass with solvent, 1

40 prefer to adjust the water content thereof to erol will not be broken. Then when the saponifled satui'ated fatty acids are removed from the partially saponified mixture, the fatty material which remains'will be more highly unsaturated than the original material. However, if the conditions of saponification are made somewhat more severe the unsaturated fatty acids will be split off from the glycerol just as readily as the saturated ones, and therefore in such cases the degree of unsaturation of the unsaponified fatty ma.- terial, for all practical purposes, will not have been increased whatsoever.

In selectively and partially hydrolyzing the fatty material with caustic alkali, the partial saponiflcation may be carried out without the'presence of a solvent; however, it is preferred to carry out this step in the presence of a solvent for the oil, such as a hydrocarbon or halogenated hydrocarbon solvent. Suitable solvents in which the animal or vegetable oil may be selectively and partially saponified include,.inter alia, ethylene dichloride, methylene dichloride, trichloroethylene, heptane, hexane, cyclohexane, methyl cyclohexane, etc., or a mixture of two or more. of

, is preferably effected by slowly stirring aqueous about 22% to about 26% based on the weight of the soap present in the mass, as separation of the saponified portion from th unsaponifled portion is most efllcientLv accomplished when the moisture content of the soap mass is within this range. 0f course, the oil may be separated from the soap by other means, e. g. centrifugation, etc., if desired.

Any animal or vegetable fatty material containing unsaturated fatty acid radicals may be treated by the process of the invention. Fatty materials which may be treated include, inter alia, soybeans oil, wheat germ oil, corn oil, com germ oil, perllla seed oil, linseed oil, olive oil, teaseed oil, cottonseed oil, sesame seed oil; peanut oil, palm kernel oil, locustseed oil, coconut oil, cranberry seed oil, grapeseed oil, nut oils, e. g. walnut oil and pecan oil, grapefruit seed oil, fruit oils, lard oil, whale oil, seal oil, butter oil, porpoise oil, tomato seed oil, neats-footoil, etc. Also, if

' desired, mixtures of any of these or other animal or vegetable fatty materials may be selectively partially saponified by the process of the invention.

The following table summarizes a few of the many experiments carried out on various oils of vegetable and animal origin under varying conditions. I In each case parts of fatty material were saponified with an amount of 45.5% aqueous potassium hydroxide sufficient to give the percentage of saponification as indicated in the table In each case, 3 parts oi isopropanol were employed as a saponiflcation catalyst, and the saponiflcation was carried out at room temperature with mild agitation of the reaction mass. When matter.

the saponiflca tion was carried out in the presence of a solvent, 50 parts of ethylene dichloride were dissolved in 100 parts of oil. Upon the completion of the partial saponiflcation, the partially saponiiied-mass was mixed with 300 parts of ethylene dichloride, and the mixture warmed to about 40 C. to coagulate the soaps. The moisture content of the soap was then increased to about 2425%, and the mixture then cooled to about 25 C., and the unsaponified fraction extracted with additional batches Of fresh solvent. The extracts were then filtered, and the fatty material recovered therefrom by removing the solvent by distillation under reduced pressure.

Table l 8 nm Iodine value apo 011 cation Conditions Original Final Per cent Crude wheat germ 25 Solvent. 123 126 50 123 133 75 123' 140 52 172 184 69 172 181 73 172 182 D0.-........ 79 172 178 Crude cotton seed oil. 80 do 100 114 0...... 82 Ne solvent. 100 113 Reiilned cotton seed 81 Solvent. 110 122 Do:..... 83 No solvenL. 110 118 Teaseed oil 77 Solvent. 84 89 Do...... 81 No solvent. 84 87 Crude corn oil. 72 Solvent. 118 133 Do 75 No solvent. 118 128 Crude corn germ oil.. 72 Solvent. 126 132 Do. 77 No solvent. 126 128 Crude peanut oil 73 Solvent. 90 97 Do. 77 No solvent.. 90 95 Crude sesame oil 75 Solvent..... 112 119 Do 77 No solvent 112 115 Refined soybean 011.. 72 Solvent. 123 136 o 80 No solvent. 123 133 Crude coconut oil.... 81 Solvent. 9.1 15. 5 o 88 No solvent.. 9.1 12.2 Palm kernel oil 69 Solvent. 14 25. 5 D 92 No solvent. 14 24. 2

75 Solvent. 99 109 81 No solvent. 99 106 63 Solvent. 28 36 83 do 69 76 85 No solvent 69 74 72 Solvent. 81. 5 89. 5 Do... 80 No solvent 81.5 87 Rancid olive oil 77 Solvent. 65 73 Crude perilla oil. 43 No solvent.. 1B7 191 D 72 d0 r 187 193 Crude cranberry seed oil 65 Solvent. 156 171 It will be noted that in every case, greater selectivity was secured by carrying out the saponification in the presence of ethylene dichloride.v

From the foregoing description it is apparent that the iodine value of oils of animal and vegetable origin maybe readily increased. Such products, depending upon their final degree of unsaturation, have many uses in industry such as drying oils, raw materials for the preparation of sulfated wetting agents and emulsifiers, as raw materials to be sulfurized, blown and polymerized, etc. Moreover, the soaps produced in accordance with the process of the invention are highly im-' proved in character due to the absence of the more unsaturated components and unsaponiflable The expression animal and vegetable oils is employed herein to connote all oils, whether classified as dryin'g, semi-drying or nondrying, obtained from animal and vegetable origin, the latter including any form of vegetation.

Since certain changes may be made in carryin out the above process without departing from the scope of the invention, it is intended that all matter containedin the above description shall tity of a hydrocarbon solvent therefor, saponifybe interpreted as illustrative and not in a limitins sense.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is: 1. A process of increasing the iodine value of animal and vegetable oils which comprises partially and selectively saponifying to 95% of an oil selected from the group consisting of animal and vegetable oils by means of an alkali to split saturated glycerldes and separatingthe unsaponified fraction from the resulting mass.

2. A process of increasing the iodine value of animal and vegetable oils with a lesser quantity.

of a water-immiscible organic solvent therefor,

saponifying 25% to 95% 01 the oil by means of an alkali and separating the unsaponifled fraction from the saponified mass.

3. A process of increasing the iodine value of animal and vegetable oils which comprises admixing an oil selected from the group consisting of animal and. vegetable oils with a lesser quaning 25% to 95% of the oil by means of an alkali and separating the unsaponifled fraction from the saponificd mass. 4

4. A process of increasing the iodine value of I animal and vegetable oils which comprises ad:

of an alkali and separating the unsaponifled fracv tion from the saponified mass.

5. A process of increasing the iodine value of animal and vegetable oils whichcomprises ad mixing an oil selected from the group consisting of animal and vegetable oils with a lesser quantity of ethylene dichloride, saponifying 30% to or the oil by means of an alkali and separating the unsaponifled fraction from the saponified mass.

6. A process of increasing the iodine value of animal and vegetable oils which comprises admixing an oil selected from the group consisting of animal and vegetable oils with a lesser quantity of a hydrocarbon solvent therefor, saponlfying 25% to of the oil by means of an alkali in the presence of a saponifying catalyst and 'sep-.

arating the unsaponifled fraction from the saponined mass.

v7. A process of increasing the iodine value of mixing in the presence of an alcoholic saponification catalyst an oil selected from the group consisting of animal and vegetable oils having a lesser quantity of a water-immiscible organic solvent dissolved therein with a quantity, of alkali sufllcient to saponify 25% to 95% of saidoil, stirring the mass to form a super-solvented emulsion,

reaking the emulsion by means of heat to floccuate the soap, adding a further .quantity of waterimmiscible organic solvent-to cause complete separation or the flocculated soap particles and sep-,

arating the solventsolution of the unsaponifled high iodine value 011 from the soap particles.

9. A process of increasing the iodine value 01' animal and vegetable oils which comprises admixing in'the presence of an alcoholic saponiflcation catalyst an oil selected from the group consisting of animal and vegetable oils having a lesser quantity of ethylene dichloride dissolved therein with a quantity of, alkali suflicient to saponify 25% to 95% 01 said oil, stirring the mass to form a super-solvented emulsion, breaking the emulsion by means of heat to fiocculate the soap, adding a further quantity of ethylene dichloride to cause complete separation of the fiocculated soap particles and separating the solvent solution of the unsaponified high iodine value 011 from the soap particles.

10. A process of increasing the iodine value of animal and vegetable oils which comprises admixing in the presence of isopropanol an oil selected from the group consisting of animal .and vegetable oils having a lesser quantity of ethylene dichloride dissolved therein with a quantity of alkali suficient to saponify 30% to 90% of said oil, stirring the mass to form a super-solvented emulsion, breaking the emulsion by means of heat to flocculate the soap,

30% to 90% of said 011, stirring the mass to term a super-solvented emulsion, breaking the emulsion by means of heat to fiocculate the soap, adding a further quantity of ethylene dichloride to-cause complete separation of the flocculated soap particles and separating the solvent solution of the unsaponified high iodine value 011 from the soap particles.

12. A process of increasing the iodine value of soya bean oil which comprises admixing in the presence of isopropanol soya bean oil having a lesser quantity of ethylene dichloride dissolved therein with a quantity of alkali sufllcient to saponify 30% to 90% of said oil, stirring the mass to form a super-solvented emulsion, breaking the emulsion by means of heat to flocculate the soap, adding a further quantity of ethylene dichloride tocause complete separation of the flocculated soap particles and separating the solvent solution of the unsaponified high iodine value oil from the soap'particles.

13. A process of increasing the iodine value of cranberry seed oiLwhich comprises admixing in the presence of isopropanol cranberry seed oil having a lesser quantity of ethylene dichloride dissolved therein with a quantity of alkali suflicient to saponify 30% to 90% of said oil, stirring the mass to form a super-solvented emulsion, breaking the emulsion by means of heat to flocculate the soap, adding a further quantity of ethyiene dichloride to cause complete separation of the fiocculated soap particles and separating the solvent solution of the unsaponifled high iodine value oil from the soap'particles.

t LORAN OID BUXTON. 

